Piston packing



Aprll 12, 1927' E. McFAL L PISTON PACKING Filed June 14, 1926 7 V fact that the rings cannotfit snugly against the piston the packing is asso- Patente d Apr. 12, 1927.

i .THUBLOW n. McFALL, orsranra, rome in.

' risron rnok'ine.

Application .fi lei l June 14,

This invention relatesv to a piston ring packing. In engines, particularlyinternal combustion engines used in motor Vehicles, it is ery desirable that the pistons shall be 5 equipped with packing devices whichwill hold the compressiom'that .is, 'will'not permit the escape of gases downwardly past the piston into the crank case;- and also which will notl permit the passage of oil 10 upwardly past; thepist n intolthe, combustion chamber of engine with the resultant formation of carboni and use of a great deal more oil ,thanisrrequired for lubrication purposes lfi iany types of piston'rings have been devised for this purpose but from. their ery nature all are liable to permit the passage .of oil .upwardly into thecombustion chamber due to thefa ct that the ring grooves must be slightly wider than the rings which fit therein and to the further the bot OmS of saidgrooves; It islaniobject and purpose-of the present invention to provide pis ton' packing wherein passage offoil upwardly 'to "the combustion .chamber'of the engine is completely eliminated and this holds true no matter how long the packing is' used how much it may. become worn and how large v maybe the gapvat one side of the packing.

To thisendl have produced the packing fully described in the followingv description and illustrated in theaccompanying drawing, in wh ich f r v I 35, 1 's a plan View oif'one' of the packing members, or discs made in accordance inyentioni l Fig. '2isa cross section through a cylinder wherein a piston is mounted 'with at least two of the packing disc's. Fig/.3 is affi aginentary" vertical section through a cylinder and piston therein showing the {manner in which a larger number 7 ofthepacking discs nay be applied'to the piston iii spaced apart" relation to each other. Fig 4 is a View similar to Fig. 3 show-' .ing, the packing discs appliedto the piston at the'upper end'thereo'fonly. v Fig.5 is a plan Yiew ofthe upper end of ijciate d, and

ineln er A which is used to 'hold thepacking Fig.,.6'is a plan view ofthe upper securing 1926; serial No. 115,806.

In the construction of the packing fiat disc 1 of metal, preferably cast iron, is provided which at its central point is formed with an opening 20f a form such that when placed over a stud of sirbstantiallythe same form it can not rotate around the stud.

' This disc is proirided with ahelic'al slot which starts at its inner end a short distance .from the opening 2 and has/a length substantially of 540 degrees and with a-progressively increasing"width" from' its inner The metal between the to its outer end.

grooves from "its inner to itsou'ter end has a substantially progressively diminishing width so that the terminal end '5 isthe narrowest portion and is normally spaced by a gap 4 froma shoulder 6, as's'hown in Fig.

However, whenthe disc thus' .made is placed a cylinder and'the'e'nd of the-part "5 is brought adjacent the shoulderf6 and the 5 4i diminished in extent the disc at its -'per1phery assumes a circular shape so that it snugly fits theinteriorfot a piston of: the

proper diameter as shownin Fig; "2,"w'hi1e the slot 3 is of substantially Uniform width.

It is designed that'atl'east two "of these p-acking 'v discs shallbe placed at the upper end of'a piston. The piston 7 has an upper endS which at its outer edge where it joins with the'vertical' walls ofthe ;piston is cut away making the annular inclined portion 9"through*which a plurality of spaced rapartpoints downwardly and inw'ardly extending openings '10 are drilled 'tothe in-i terior "of the piston, as 'loest shown in Figs. :3 and 4'. For lightening the weight of the piston parts of theuppers'ide'8 areremoved whereby the upper end of the piston has the appearance of a wheetwitliradiatingspokes is threaded for at 'purposethat will later pp r- 1 I flOneof the packing discs ie-placed, over the stud 12 against the-upper 'end 8 ofithe piston and over a this packing disc a second and central hub 11 from-which astud 12 extends-upwardly "of a-form such that it will pass through and fit .the opening 2 in the disc is placed but turned to a position half -i way around th'e :pistonso that the lgapsx i in the .packings lieIat diametrically opposed .fsides ofpthepistoni-* lWhenthus placed together .tlie-slot-3 inthe' lower packing disc is A completely ,Ioovered by L-the. :metal in: ;the

upper thesIot-inLthe-npper discat I l "discsmay 'be used with piston. In this] gin es.

no point comes into conjunction with the slot 3 in the lower disc. This is fully shown in Fig. 2.

After the packing discs, at least two, have been thus placed together, an upper securing member is threaded onto the cylindrical projection 13. This member includes a central hub 14 with a threaded opening 15 therethrough, spokesradiating from the hub and an outer annularv ring 16, the outer diameter of the ring 16 being slightly less than the diameter of the piston. This can be threaded onto the stud .13 and hold the discs in place, the hub 14- comin; against the upper end of the stud 12 and leaving; a very small spaceso that the tendency of the packing discs to spring outwardly is not restrained inany manner. 7

With the packing discs applied to a piston in the manner described and as fully illustrated in Fig. 4. on the down stroke of the piston. oil will be scraped from the walls of the cylinder into the annular recess underneath the outer edge portions of the lower packing discs which is made by removing the upper annular corner ofthe piston at 9 and this oil will be directed through the openings 10 to the interior of the piston where it will fall into the crank case. There is no possibility. such as occurs with piston rings in ring grooves, of the rings battering and widening the grooves and of oil passing'under-neath the-rings into the nrooves on the down stroke of the piston and thence upwardly inside of andover the rings to a point above the same so that it eventuallv reaches the combustion chamber. 7. Any oil which may pass through the gap 4 into the spiral groove 3 in the lower packing: disc cannot escape upwardly into the combus- 'tion chamber as the grooves 3 in the two packing: discs do not cross each other at any point and there is no communication estabhshed in this manner. 'The packing discs completely eliminate any tendency to oil pumping or any other method wherebythe oil can pass upwardly into the combustion ehamber of the engine and this holds true irrespective of how much the discs may be "worn at their outer edges or how much the aps 4 may widen with such wearing. Furthermorethe packing. by reason of itsconstruction. bears with substantially uniform pressure against the inner walls of the cylinder and makes a very practical. substantial. and efiicient packing for pistons. particularly pistons of mternalcombustion en- In Fig: 3 a construction isshown wherebva pluralityof the pairs of the packing:

phase-the piston 7 i's'const ructed" identically wit-h that'shown 'in Fig. 4 except the stud 5 "19is lonizer than-the stud l-Qshow'n in Fig. I

4 so that it may pass upwardly through a signed. against 011 pumping or Oll passage to the discs being; formed with a helic manner as before described. While one only of the piston sections 7* is shown it is obvious that any desired number'may be used so as to increase the numbers of packing discs to any desired degree. It is, of course, to be understood that the packing; discs are not clamped and bound between the upper end of the piston 7 and the lower side of the section 7* except possibly at the center so that the tendency of the discs to spring outwardly is not destroyed.

This construction of packing has been tested and tried out thoroughly and has proved very practical and efficient for the attainment of the ends for which it is de' Particularly it is an insurance combustion chamber of the engine; and this, insurance remains a quality of the packing during the entire time that it is used irrespective of wear on the edges of the packing discs.- Theinvention is defined in the appended claims and is to be considered comprehensive of all forms of structurec'oming within their scope.

, I claim:

' 1. A piston termed with a thereof starting a short distance From the center of the disc and progressively appackingr comprising; a flat disc -proaching the periphery of disc and joining with a gap cut inwardly from the outer edge oi the disc, substantially. as described. I Y I 2. A piston packing comprising aflat disc of metal having a helical slot therethrough theinner endof which lies a short distance from the center of said disc. said slot pro-v vejressively approachin q the-periphery of the disc and atitsouter end joining with a gap cut inwardly from one edge ot said disc. the metal at the outer sides of said slot tending to spring outwardly but being compressible so that the disc will assume a circularshape when in compressed form.

3. In combination witha piston. a plurality oi -flat discs laid. one over the other at the upper end ot the'piston,

means for holding said discs on the piston. each of .said

al slot but therethroue'h. the inner end otwhiclrlies closely adjacent the centerotthe disc and progressively approaches I the thereot.=ioin inr at its outer end withla gap cut inwardly from-an edge of the'disc, said helical slot. the inner end a periphery 'openings for the passage of the stud and said openings and the cross section of the stud being such that the discs are held against rotation, substantially as described.

5. In combination with a piston, a stud extending upwardly from the center of the piston, a pair of flat discs having central openings through which said stud passes, said stud and openings being. so shapedthat the discs are held againstrotation and the discs lying against the upper end of the pis,

ton, each of said discs being formed with a helical slot cut therethrough, the inner end i of which is located adjacent the center of the disc, said slot in each disc progressively rip approaching'the periphery of the disc and joining with a gap cut inwardly from an 1 edge of the disc, the metal of the disc at ,s

theouter side of said slot normally springing outwardly and said discs being located so'that the slot in the lower disc is completely covered by the metal of the upper disc, and means connected to the upper end of the stud'for holding said piston, v v

6, A piston packing comprising a flat disc of metal having a central opening therediscs on the through and a helical slot cut, therein, said:

said opening and progressively approaching theperiphery of the disc and joining at its outer end with a/gap cut inwardly from an slot atits inner end being located adjacent edge of the disc, the metal at the outer side of said slot being resilient and tending to spring outwardly whereby the slot progressively widens from its inner to its outer end and the gap is relatively large, said metal at the outer side of said slots being adapted to be sprung inwardly so :as to make the slot of substantially uniform Width'and decrease the length of the gap whereupon the periphery of the disc Will be substantially a true circle. a

In testimony whereof I afiix my signature. THURLOW E. McFALL. 

